Electronic circuits frequently employ multiple voltage domains to improve various performance parameters. In one example, a low voltage domain is used for lower power operation, while a higher voltage domain is used for faster operation. Circuits that use a combination of analog and digital devices can use higher voltage domains for analog devices to achieve improved linearity or operating voltage range. Level shifters are used to interface between the various voltage domains.
Geometric scaling of semiconductor technologies has resulted in an increased voltage difference between the voltage domains, making the design of the level shifters more challenging. For example, the higher voltages can damage the gate oxide of the transistor devices used in the low voltage domain. Furthermore, high-speed level shifting is required for many systems. High-speed shifting often requires large transistor devices, however the parasitic capacitance associated with large devices reduces the level shifting speed.